An apparatus which projects lights of different colors, such as a projector, includes an excitation light source configured to emit excitation light of a single color, and a phosphor wheel having a diffuser plate configured to receive the excitation light from the excitation light source and transmit therethrough while diffusing the excitation light and a phosphor layer configured to receive the excitation light and emit fluorescence of colors different from the color of the excitation light. The apparatus causes the excitation light source to irradiate the diffuser plate and the phosphor layer of the phosphor wheel rotating with excitation light and extracts light of a plurality of colors to form images to be projected (for example, refer to JP-A-2012-068528).
The phosphor wheel of JP-A-2012-068528 includes transmissive sections formed by fitting arc-shaped phosphor layers and arc-shaped diffuser plates in the same circumferential band of a wheel plate.
The phosphor wheel having the above-described structure has a problem that when the phosphor wheel rotates at high speed, the centrifugal force may cause misalignment or separation of transmissive members such as the diffuser plates, resulting in malfunction of the phosphor wheel.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a phosphor wheel capable of reducing or preventing misalignment and separation of transmissive members.